Thumb wrestling
You got exposed to kryptonite.
Then you look really shifty-eyed and adjust your glasses and mumble “…uh, I fell, really, that’s it” and make a break for the nearest closet. But first mention the kryptonite.
[nitpick] this gal. [/nitpick]
Oops. I have unwittingly revealed my LOTR ignorance. (I think that’s a pretty serious character flaw around here.)
One of my neighbor’s grown sons broke his leg lighting a cigarette. I’m still a little vague on exactly how.
Tell 'em you broke your thumb playing harmonica. That’ll confuse them long enough for you to run away before they pursue that line of inquiry.